Cutter assembly for oil well tools



Feb. -9, 1937. J. A. ZUBLIN CUTTER ASSEMBLY FOR OIL WELL TOOLS FiledJune gz, 193s k ll M 1111 A. Zl/bl/[I l P WE a E m. .2 N

Patented Feb. 9, 1937 UNITED STATES Y PATENT OFFICE While the presentinvention relates genera y to oil well tools, it is especially concernedwith.

replaceable cutter assemblies for tools adapted to operate in relativelyhard formations. These cutter assemblies may be'used in various toolshaving diflerent uses, and reference may be had to my copendingapplications for typical tools. A drill bit is shown in my twoapplications on Drill bit with rolling cutters, Ser. No. 56,252, fliedDe-.

cember 26, 1935, now Patent No. 2,050,989 and Ser. No. 71,600,filedMarch 30, 1936 now Patent No. 2,050,988; while my applicationsentitled "Core drill Serial No. 86,688, and "Reaming tool" Serial No.86,687 filed on even date herewith show various core barrels and reamersusing these assemblies.

For reasons well known in the art, tools for use in rock and other hardformations generally use rolling cutters since they produce the best.

To permit adequate kind of cutting motion.

penetration of the formation, the cutters are small and have only asmall number of teeth in contact with the formation at onetime. Bymounting a number of such rollingcutters on a carrier which is in turnrotatably mounted upon crease in total cutting surface greatly lengthensthe lifeof the tool and the distance 'it will drill before becomingdull.

My previously filed applications have shown all the roller cutters onone'carrier in one and the same position. However, since the carrierrotates in only one plane, difierent positions'of cutters 40 on the samecarrier are advantageous for various reasons. For example, on sometools, a combination of cutting positions may be desired, so that thecutters will cut on portions of the hole which are at angles to eachother, as the sides and bot- 45 tom of the hole, or in some formations adifferent or combination motion of the various cutters will be'mostefllcient; or it may bedesired to change a portion of the cutters toinfluence the speed of carrier rotation, as described in my prior ap- 50pllcations. v

It is also a distinct advantage to have the cutter assembly made as aunit. The tool shank is subjected to very little wear and will outlast agreat fraction is operative at any one time. The incarrier by weldingsince this procedure is simple, inexpensive, and, most important, it iseffective in preventing loss of cutters. The carrierwith its attachedcutters is treated as a unit and the complete assembly is readilydetachable from the tool 5 shank when the cutters are worn. For thisreason the replacements are not single cutters, but an entire assemblymanufactured as a unit in a factory and shipped, as a separate articleof manufacture, to the field where it is inserted in a 10 tool shank inplace of an assembly with worn cutters.

It is a general object of my invention to provide on a cutter carrierwhich rotates in one plane, a numberof cutters which move with a 15substantiallyrolling motion over different faces of the formation whichlie at various angles to each other and to the plane of the carrier.

Thus it is also an object 'of my invention to make a cutter assemblywith rolling cutters that go issimply and easilymade and handled as aunit,

' and can be mounted on a tool body to give a large amount ofcutting'surface with only a small part active at any one time. a Anotherobject is to provide a cutter assembly a with cutters mounted to revolveabout axes at angles to each other so that various cutters have,.diiferent rolling motions that combine to produce a particularlyeffective cutting action.

Another object is to provide a cutter assembly in which the cutterpositions canbe adapted to suit various tools and types of drillingconditions.

'Ihese objects are attained in my improved cutter assembly by using awheel-like carrier that can be rotatably mounted on the tool body.

Around the rim of the carrier are mounted anumber of rolling cutterswith certain cutters or groups of cutters mounted to rotate about axesat an angle to the axes of other cutters. Preferably the cutters areplaced in two or more groups, the axes being similarly disposed withineach group, but differently disposed between groups.

How the above. and other objects and advantages of my invention areattained will be more clearly understood by referenceto the following4:!

description and annexed drawing, in which:

, Fig. lis a side elevation of a cutter assembly, partially broken away;

Fig. 2 is a vertical section on line 2-4 of Fig. 1;

Fig.- 3 is a side elevation of a variational form of cutterassembly:

Fig. 41s a vertical section on line 4-'-l of Fig. 3;

Fig. 5 is a side elevation of another variational u form of cutterassembly;

- termed similar.

shape suitable to permit rotational: mounting of the carrier so thatit.revolves about a central axis; or the carrier may have an integrallyformed shaft.

The carrier may be provided on one orbothside faces withan annulargroove l2, which forms part of a channel to hold ball bearings thatprovide a thrust bearing between the carrier and an adjoining member,which may be either another carrier or a portion of a tool body.

About the periphery of the carrier and extending radially inwardlytherefrom are a number of slots i4 and I5 of suitable size and shape toreceive one ofthe roller cutters 24. Adjoining each of these radialslots is a pair of notches [6 adapted to receive an axle pin I8 uponwhich the cutters are rotatably mounted. Notches l6 are located onopposite sides of the slots so that the axle pins extend across them.The pins l8 may be secured in place by any suitable means but arepreferably welded to the carrier, as at 20, since this is a very simpleand economical means of safely securing the pins in place.

As a means of conducting circulation fluid to opening II in order toprovide lubrication for the bearing, circular passage 2 l .connects thebottoms of slots l5, and radial passages 22 connect with slots I4, I 5and passage 2| to conduct fluid to opening II.

The roller cutters 24 are preferably substantially cylindrical in shape,and provided with cutting teeth which may have any desired shape andspacing. The cutters 24 that are placed in slots l4, lie entirelybetween the side faces of the carrier but project radially beyond theperiphery of the carrier where they come into cutting engagement withthe formation; while the cutters that are placed in slots l5 do notextend radially beyond the carrier, but are so placed asto projectbeyond one side face of the carrier where they giome into cuttingengagement with the forma- It will be seen that the cutter assembly inFig; 1 -is provided 'with two groups of cutters. Onegroup is mounted torotate about similar axes which are parallel to each other and to theaxis of carrier rotation, and consequently perpendicular to the plane ofcarrier rotation. Another group of cutters is mounted to rotate aboutsimilar axes which lie in a plane of carrier rotation and are tangentialto the carrier axis. The

phrase a plane of carrier rotation is usedto include any planeperpendicular to the axis of carrier rotation and lying between the sidefaces of the carrier, and is not to be construed as limited to themedian plane of the carrier perpendicular to its axis.

Since in each group the axes have these common or similarly definedpositions, they are It will be noted that the axes of one group are atan angle to the axes of the other group, in this particular instance theangle being a right angle. While the location of the cutters may be .asdesired, they are preferably located as shown with successive cuttersbelonging to alternate groups.

The cutter assembly shown in Fig. 3 is generally similar to the onealready described, except that slots l5 have been replaced by'adifferent type of slot 26. Cutters 24 are mounted in. these slots bymeans of axle pins l8a which have. a head on one end and are tightlyseated in a single notch Isa in the carrier. Taper pin 28 holds the axlepin in place and the large end of the taper pin is welded to the carrierto hold it against removal. To facilitate removal of the taper pin, thebore holding it is continued on at the small end through the carrier at29, so that an instrument may be inserted to drive out the pin.

Like the cutters in slots IS, the cutters in slots 26 come into cuttingengagement with the formation only by projecting beyond one side face.of the carrier and do not project radially beyond the carrier.

As before, the carrier of Fig. 3 is provided with two groups of cutters,each group rotating about similar axes. In this form of assembly,

the axes of one group are all parallel to the cutter axis, while theaxes of the other group of carriers all lie in a plane of carrierrotation and extend radially from the carrier axis.

The form of carrier shown in Fig. 5 represents another combination ofthe three groups of cutters described in connection with the earlierfigures. The carrier is provided with slots l5, as

in Fig. 1, and with slots 26 as in Fig. 3, and

of cutters within a group may lie in difierentplanes of rotation.

The axes of the cutters in groups so far described have been eitherparallel, or radial, or tangential with respect to the carrier axis.These axial relationships generally correspond to the 2:, .y, and z axesof solid geometry and so involve as a rule a right angle relationbetween any two groups, though the groups may be combined, as in Fig. 5,to give an oblique relation. It will, of course, be evident that theaxes may occupy one of various intermediate positions, two other obliquepositions being shown in Figs. '7 and 8. In Fig. '7, pin IN) is tiltedfrom a position parallel to the carrier axis so that it is inclined to,and when projected intersects; the carrier axis. In Fig. 8, pin lac hasbeen inclined so that it is no longer parallel to the carrier axis butstill lies in a parallel plane, and. so will not intersect the carrieraxis when projected. From" these two examples, it will be understood howthe other pins may be tilted to give a number'of different combinationsof cutter axes, and under these circumstances the axes of the variousgroups of cutters are oblique to one another rather than at right anglesor perpendicular, as in Figs. 1 and 3.

Inspection of the drawing will show that the cutters on a carrier may begrouped in various ways and may be arranged in more than two groups,depending upon'the definition or common characteristic of the axes usedto determine the group. Also, each of the groups may have varyingnumbers of cutters, difierent groups not of the hole being drilled, asthe sides and bottom.

The cutters effectively attack parts of the formation lying at difierentangles to each other and to the carrier even though the carrier revolvesin only one plane.

It will be understood that changes may be made in the construction andthe arrangement of the various parts without departing from the spiritand scope of my invention, and it is therefore to be understood that the-appended claims are illustrative of rather than restrictive upon thebroad scope oi!v my invention.

I claim as my inverition;

l. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be rotatably mounted on the tool body, and a plu-'rality of cutters rotatably mounted on the' carrier, one group ofcutters being mounted to rotate about similar axes'relative to thecarrier axis and another group of cutters being mountedto rotate aboutsimilar "axes at a different angle tot-he carrier axis.

2. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be rotatably mounted on the-tool body, and aplurality of cutters rotatably mounted on the carrier,\ one group ofcutters being mounted to rotate about similar axes relative to thecarrier axis and another group of cutters being mounted to rotate aboutsimilar axes at a different angle to the carrier axis, successivecutters belonging to alternate groups.

3. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be rotatably mounted-on the tool body, and aplurality of cutters rotatably mounted on the carrier, one group ofcutters being mounted to rotate about ,axes parallel to the carrier axisand another group of cutters being mounted to rotate about axes that areinclined to the carrier axis.

4. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be rotatably mounted on the tool body, and aplurality of cutters rotatably mounted on the carrier, onegroup ofcutters being mounted to rotate about axes lying in a single plane andanother group of cutters being mounted to rotate about axes similarrelative to the carrier axis and at an angle to said plane.

5. A cutter assembly for an earth boring tool the carrier.

rotate about axes similar relative to the carrier axis and that are atan angle to said plane.

x 6. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be rotatably mounted on the tool body, and aplurality of cutters rotatably mounted on the carrier, one group ofcutters being mounted to rotate about parallel axes at an angle to theplane of carrier rotation and another group of cutters being mounted torotate about axes that are similar relative to the carrier axis and thatare oblique and oppositely disposed to the axes of the first group.

'7. A cutter assemblyfor an earth boring tool comprising a wheel-likecarrieradapted to be rotatably mounted on the tool body, and apluralityof cutters rotatably mounted on the carrier, one group ofcutters being mounted to rorier rotation.

8. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be rotatably mounted on the tool body, and aplurality of cutters rotatably mounted on the carrier, one group ofcutters being mounted to rotate about tangential" axes lying in a planeof carrier rotation and tangent to a circle of rotation and anothergroup of cutters being mounted to rotate about. axes parallel to theaxis of carrier rotation.

9. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be roed to rotate about axes parallel to the axis ofcarrier rotation.

10. A cutter assembly for an earth boring tool comprising a wheel-likecarrier adapted to be rotatably mounted on the tool body, and aplurality of cutters rotatably mounted on the carrier, one group ofcutters being mounted to rotate about radial axes lying in a plane ofcarrier rotation, and another group of cutters being mounted to rotateabout tangential axes lying in a plane of carrier rotation and tangentto a circle of rotation.

11. A cutter assembly for an earth boring tool comprising a Wheel-likecarrier adapted to be r0- tatabl y mounted on the tool body, and aplurality of cutters rotatably mounted on the carrier, one group ofcutters being mounted to rotate about similar axes and another group ofcutters being mounted to rotate about similar axes that are at an angleto the axes of the first group, the. cutters of one group lying entirelybetween the side faces of the carrier and projecting radially beyond thecarrier, while the cutters of the other group extend beyond only oneside face of JOHN A; ZUBLIN.

CERTIFICATE OF CORRECTION.

Patent No. 2,069,795. I February 9, 1937.

JOHN A. ZUBLIN;

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 3,second column, line 2, claim 5, strike out the words ','that are"; andthat the said Letters Patent. should be read with this correctiontherein, that the same may conform to the record of the case in thePatent Office Signed and sealed this 11th day of May, A. D.'-' 1937-.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

